JPH0242668A - Reproducing device - Google Patents

Abstract

PURPOSE:To shorten the necessary time of retrieving action by executing a search through the use of a reel rotating speed ratio to be recorded beforehand. CONSTITUTION:The positions of respective main data on a magnetic tape 22 are stored by being replaced with the rotating speed ratio of the reel, and by comparing the stored rotating speed ratio corresponding to the main data of a reproduction purpose with the rotating speed ratio of the reel at the time of a rapid traverse and a rewinding, the retrieval of the main data of the reproduction purpose is executed. In the retrieval of the main data by the rapid traverse and rewinding, the most traveling section of the magnetic tape 22 can be retrieved by executing the traveling at a high speed to exceed a traveling speed at which heads 23a and 23b can read subcode data recorded on the magnetic tape 22. Thus, the necessary time of the retrieving action can be widely shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a digital audio tape recorder (D
digital＾dio Tipe recorder;
It relates to a playback device used for example (abbreviation: DAT).

Conventional technology In digital audio tape recorders.

The magnetic tape, which is the recording medium, has a main data recording area for recording main data and a subcode data recording area for recording subcode data related to the main data. A common method is to read out the corresponding subcode data as well. For example, if several pieces of music are sequentially recorded in the main data recording area as main data, subcode data related to each of them may include song number information, time information, information indicating the beginning position of the song, etc. are sequentially recorded in the subcode data recording area in association with each song, and based on these subcode data, you can locate the beginning of the song you want to play, or select an arbitrarily selected song number. can be played in any order.

FIG. 5 is a block diagram showing a schematic configuration of a conventional example of a playback mechanism in the above-described digital audio tape recorder.

The rotary drum 1 is for reading data recorded on a magnetic tape 2 which is a recording medium, and on the outer circumference of the rotary drum 141 there are drums arranged at intervals of 180 degrees in circumferential angle.
A pair of magnetic helads 3a, 3b is provided. The magnetic tape 2 is wound around the outer peripheral surface of the rotating drum lxl over a constant circumferential angle, and the magnetic tape 2 is wound around the outer peripheral surface of the rotating drum l
As a result of the rotation of
The data is read by scanning.

The reel motor 4a is a drive source for driving a supply reel (not shown) to which the end of the magnetic tape 2 is fixed, and another reel motor 41 is a drive source for driving a supply reel (not shown) to which the starting end of the magnetic tape 2 is fixed. This is a drive source for driving the take-up reel. Rotational speed detection sensors 5a and 5b are provided near each reel motor 4a and 4b to detect their rotational speeds, respectively.

The reel motor control circuit 6 controls each reel motor 4; I, 4b.
The drum motor control circuit 7 is a circuit for controlling the rotation speed of a drum motor (not shown) that drives the rotating drum 1. The reel motor control circuit 6 and the drum motor control circuit 7 are controlled by a system control circuit 8. A system control circuit 8 is a circuit for controlling the entire system, and each magnetic head 3 a * 3 of the 0-rotation drum 1
b is connected to the regenerative amplifier 9. This is a circuit for amplifying the signal read from the magnetic tape 2 by the reproducing amplifier magnetic heads 3a, 3b, and is connected to the next stage signal processing circuit 10.

The signal processing circuit 10 is a circuit that performs error correction after demodulating an input signal into a digital signal before recording.
It is connected to the next stage digital-to-analog conversion circuit 11 and subcode signal reproduction circuit 12. The digital-to-analog conversion circuit 11 converts PCM (Pulse Code Mo.
duration) signal and converts it into an analog signal.The converted analog signal is amplified by the next stage regenerative amplifier 13, and then sent to the speaker 1.
4, the original music is played back.

The subcode signal reproducing circuit 12 takes out the subcode signal from the digital signal obtained by the signal processing circuit 10, and
The display circuit 15, which has the function of sending this to the system control circuit 8, displays subcode data such as the track number and playback time in accordance with the subcode signal sent to the system control circuit 8. The key input circuit 1G uses key operations (? to play, fast forward (fast forward the magnetic tape 2 from the supply reel to the take-up reel), and rewind the magnetic tape from the take-up reel to the supply reel).
A circuit for giving commands to the system control circuit 8, such as search (searching for the beginning position of a song to be played), and song number memory (memorizing a ten-digit song number corresponding to the recorded song). It is.

Next, f! is recorded on the magnetic tape 2 by the digital audio tape recorder described above. We will explain the operation of the 4-kai, which alternately repeats and plays two songs out of a number of songs.

Figure 3 is a timing chart showing the playback operation.
Among them, the third @ (1) shows the recording status of each person on the magnetic tag 2E, and the signal shown in FIG. 3 (2) is one of the subcode data and indicates the recorded head position of each person. (hereinafter referred to as star ID).
Figure (3) shows the changes in the positions of the magnetic heads 3a and 3b on the magnetic tape 2 during playback operation using solid lines. N
It is assumed that the th song and the N+5th song are repeatedly played.

First, by detecting the rising edge of the start IDa corresponding to the Nth song at the time of TO in FIG. 3(3), the Nth song is reproduced in section T1 in FIG. 3(3). Next, at the time T2 in FIG. 3 (3), the magnetic head 3a
, 3b, the start I corresponding to the N+-1st song is
When the rising edge of Db is detected (that is, when the N+1st song is detected), the operation shifts to searching for the N+5th song. This search is performed by counting the number of start IDs from among the subcode signals read by the magnetic heads 3a, 3b in the fast-forward section T3 shown in FIG. 3(3).

If you count the start ID 5 times, that is, the 311th W (2
) when the rising edge of start IDc of ) is detected
It is assumed that the start position of the +5th song has been detected, and at this time T4, the reel motor 4a is activated.

The brake is applied to 4b. After the magnetic tape 2 is braked due to the inertia of the reel, it overshoots by section T5, and at T6, the reel switches to reverse rotation, and in the next section T7, star 7-I D c corresponding to the N+5th song. edges are detected again. Even after the edge of the start IDc is detected, the reel continues to run for a certain amount of time, and at time T8, the reel is switched to normal drive and the magnetic tape 2 is fed at the normal playback speed.

In this way, continuing the reverse rotation for a while is N+5'#
This is to ensure a run-up section T9 necessary for playing the first song. After this, at T10, Star 1-I D
When the rising edge of c is detected, the subsequent section Tl
At l, the N+5th song is played.

Next, at time T12, when the rising edge of the start ID a shown in FIG. 3 (2) is detected, that is, N
+6th song start position is detected), the operation shifts to searching for the Nth song. This search is also shown in Figure 3 (3).
This is done by counting the number of start IDs in the rewind section 713 shown in FIG. Time T1 when the rising edge of the start IDa corresponding to the Nth song is detected
At 716, the brakes are applied to the reel motors 4a and 4b, but the magnetic tape 2 has gone too far by this island and section T15, and at 716, the reel is switched to forward rotation and the magnetic tape 2 is played back at the normal playback speed. The same operation as that after the time To described above is repeated through the run-up section T17 after 2.

Problems to be Solved by the Invention By the way, in the conventional playback mechanism described above, in order to search for a song to be played, the magnetic tape 2 is fast-forwarded or rewound, and the beginning of the song recorded on the magnetic tape 2 is searched for. Since subcode data such as position information and track number information must be read by the magnetic heads 3a and 3b, the running speed of the magnetic tape 2 at this time is such that the subcode data can be read by the magnetic heads 3a and 3b. There was a problem that the search operation was time-consuming due to the limited range.

Figures 6 to 8 illustrate the principle that the probability that data recorded on the magnetic tape 2 will be read by the magnetic tape 3a, 3b during fast forwarding or rewinding is lower than during normal playback. FIG. 6 is an explanatory diagram of the magnetic head 3a during normal reproduction.

3b and the recording track 17 on the magnetic tape 2. 1 is a magnetic head 3a during fast forwarding.

3b and the recording track 17 on the magnetic tape 2, FIG. 8 shows the relationship between the magnetic head 3εt during rewinding.

3b and the recording track 17 on the magnetic tape 2.

No. 6 (magnetic tape 2 in normal playback operation shown in 21)
If the velocity vector of is expressed as vt, and the velocity vector of the magnetic heads 3a and 3b is expressed as ■, then the traveling velocity vector V of the magnetic heads 3a and 3b on the magnetic tape 2 overlaps with the recording l/rack 17. That is, the magnetic heads 3a and 3b scan the recording track 17 in the same direction as the recording track 17.

On the other hand, in the case of fast forwarding as shown in Fig. 7, the magnetic tape 2
Since the velocity vector ■t1 of is larger than the velocity vector ■ of normal reproduction, at this time, the magnetic helad 3a,
The speed of magnetic heads 3b is also increased as shown by speed vectors ■ and 11, and the scanning speed vectors of magnetic heads 3a and 3b become ■□
It is set so that That is, in the scanning velocity vector v, II at this time, the component in the direction parallel to the recording track 17 is the scanning velocity vector during normal reproduction.
, is set equal to .

This is because if these are not equal, the reading speed of signals by the magnetic heads 3a and 3b will be different during normal playback and during fast forwarding.
This is because the loop) circuit must be switched between normal playback and fast forwarding, which would make the circuit extremely complex. In this way, during fast forwarding, the scanning direction of the magnetic heads 3a, 3b is deviated by an angle θ□ with respect to the recording track 16.

Further, during the 1% rewind shown in FIG. 8, the running direction of the magnetic tape 2 is opposite to that during normal playback or fast forward #J session.

If the velocity vector of the magnetic head 12 at this time is V (2, then the velocity vectors V and B of the magnetic heads 3a and 3b are parallel to the recording track 17 of the scanning velocity vector V and 12 for the same reason as in the case of fast forwarding. is set so that the component in the direction of
The scanning direction b is deviated from the recording track 17 by an angle θR2.

As described above, during fast forwarding or rewinding, the scanning direction of the magnetic heads 3εi, 3b is at an angle θ with respect to the recording track 17. 1. This results in a deviation of θ,2, and this deviation increases in proportion to the running speed of the magnetic tape 2. Moreover, when the lag in the scanning direction of the magnetic heads 3a and 3b becomes large,
Magnetic heads 3a+3b of one recording track 17
The recording area scanned by the magnetic tape 2 becomes smaller accordingly, and the probability that data is read from the magnetic tape 2 also becomes smaller accordingly. For these reasons, the traveling speed of the magnetic tape 2 during fast forwarding and rewinding is limited by the magnetic head 3a, which uses data such as the beginning position of the song described above.

3b is limited to a range that cannot be overlooked.

Furthermore, in the above-described conventional playback mechanism, after detecting the beginning position of the song to be played back, the brakes are applied to the reel motors 4a and 4b to reduce the running speed of the magnetic tape 2. In order to prevent the magnetic tape 2 from traveling too far after applying the brake, it is necessary to limit the tape running speed during fast forwarding and rewinding.

Due to these limitations, even within the range of tape running speeds at which the magnetic heads 3a and 3b can read the data at the beginning of the song, as described above, fast forwarding or winding is not possible at a speed range lower than the upper limit. The search operation had to be reverted, and the search operation took even more time.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a reproducing apparatus that can significantly reduce the time required for retrieving main data to be reproduced from a magnetic tape.

Means for Solving the Problems The present invention provides a method for winding a magnetic tape on which plural main data and a plurality of subcode data respectively related to each main data are sequentially recorded from a supply reel to a take-up reel. , a reproduction means for reading each data on the magnetic tape with a head and reproducing the main data; a head position detection means for detecting the head position of the main data from the subcode data read by the head; An input for inputting a command signal to search for main data to be reproduced on a magnetic tape in a reproducing apparatus having a fast-forwarding means for fast-forwarding the magnetic tape to a take-up reel and a rewinding means for rewinding the magnetic tape from the take-up reel to the supply reel. a rotational speed ratio detection means for detecting the ratio of rotational speeds of the supply reel and the take-up reel; and a rotational speed ratio detection means for detecting when the head is scanning each main data recording area on the magnetic tape. a storage means for storing a rotational speed ratio corresponding to the main data to be reproduced in association with the main data; and a storage means for reading out from the storage means the rotational speed ratio corresponding to the main data for reproduction purpose specified by the input means, and storing the rotational speed ratio at the time of fast forwarding or rewinding. From the comparison between the rotational speed ratio detected by the detection means and the readout rotational speed ratio, it is determined that main data to be reproduced on the magnetic tape is recorded 'fRt4.
A playback device comprising: a tape speed side means for detecting when a magnetic tape approaches a scanning position of a head and slowing down the running speed of the magnetic tape until the head can read subcode data; It is.

According to the sixth aspect of the present invention, when fast forwarding or rewinding, the tape speed control means reads out the rotational speed ratio corresponding to the main data to be reproduced from the storage means, and also detects the rotational speed ratio and the rotational speed ratio. When it is detected that the recording area of the main data to be reproduced on the magnetic tape approaches the scanning position of the head by comparing it with the current rotational speed ratio detected by the means, the head reads the subcode data. The running speed of the magnetic tape is reduced until the magnetic tape can be moved.

Under this deceleration running, the subcode data on the magnetic tape relating to the head position of the main data to be reproduced is read by the head, and the main data to be reproduced is retrieved.

Embodiment FIG. 1 is a block diagram showing a reproduction mechanism of a digital audio tape recorder which is an embodiment of the reproduction apparatus of the present invention. In the figure, a rotating drum 21 is used to read data recorded on a magnetic tape 22, which is a recording medium, and on the outer periphery of this rotating drum 21, there are pairs arranged at 180 degrees in circumferential angle. magnetic head 23a,
23b is provided. The magnetic tape 22 is wound around the outer circumferential surface of the rotating drum 21 over a constant circumferential angle, and as the magnetic tape 22 runs and the rotating drum 21 rotates, the pair of magnetic heads 23a23b move around the magnetic tape 2.
2 is alternately scanned in diagonal directions with respect to its width direction to read data.

On the magnetic tape 22 described above, there is a main data recording area in which several pieces of music are sequentially recorded as main data, and a sub-data recording area in which pieces of music related to each piece of music, such as song number information, time information, and information indicating the beginning position of the song, are stored. A subcode data recording area is provided in which code data is sequentially recorded in association with each song.

The reel motor 24a is a drive source for driving a supply reel (not shown) to which the terminal end of the magnetic chip 122 is fixed, and the other reel motor 24b is a drive source for driving a take-up reel (not shown) to which the starting end of the magnetic data 22 is fixed. This is the driving source for driving the . Rotational speed detection sensors 25a and 25b are provided near each reel motor 24a and 24b to detect their rotational speeds, respectively. The reel motor control circuit 26 is a circuit for controlling the rotation speed of each reel motor 24a, 24b, and the drum motor control circuit 27 is a circuit for controlling the rotation speed of each reel motor 24a, 24b.
This is a circuit for adjusting the rotation speed of the motor (not shown).

The reel motor control circuit 26 and the drum motor control circuit 27 are controlled by a system control circuit 28. The system control circuit 28 is a circuit for controlling the entire system. Each magnetic head 23εt, 23b is connected to two regenerative amplifiers.The two regenerative amplifiers are connected to the magnetic head 23a.
, 23b, and is connected to the next stage signal processing circuit 3o. This signal processing circuit 3o is a circuit that performs error correction after demodulating the input signal into a digital signal before recording, and is connected to the next stage digital-to-analog conversion circuit 31 and subcode signal reproduction circuit 32. There is.

The digital-to-analog conversion circuit 31 is a circuit for extracting a PCM signal, which is main data, from among the digital signals that are not processed by the signal processing circuit 30, and converting it into an analog signal. is amplified by the next-stage regenerative amplifier 33, and then reproduced to the original sound by the speaker 34. Further, the subcode signal reproducing circuit 32 has a function of extracting a subcode signal from the digital signal obtained by the signal processing circuit 30 and sending it to the system control circuit 28 . Subcode data such as song number and playback time are displayed in accordance with the sent subcode signal.

The key input circuit 36 allows playback, fast forwarding,
This is a circuit for giving commands such as rewind, search, and track number memory to the system control circuit 28.

Reel rotation speed ratio calculation (ii) r!F37 calculates the circuit speed ratio of the supply reel and take-up reel based on the speed detection signal sent from the rotation speed detection sensors 25a and 25b via the reel motor control circuit 26. is calculated,
The calculation result is the system control number n28 mentioned above.
and the reel rotation speed ratio storage circuit 38 at the next stage.

The reel rotation speed ratio storage circuit 38 stores the head position of a multi-track track, which is main data, at the time of playback operation, based on the magnetic head 23a.
, 23L+, the reel rotation speed ratio sent from the reel rotation speed ratio calculation circuit 37 is stored in a space corresponding to the song number of the song.

FIG. 2 is a graph showing IIIJgh between each position of the magnetic tape 22 scanned by the magnetic heads 23a, 231) and the above-mentioned reel rotational speed ratio at that scanning position, and shows a There is a one-to-one correspondence between the position and the reel rotation speed ratio. That is, from the reel rotation speed ratio calculated by the reel rotation speed ratio calculation circuit 37, the current position of the magnetic tape 22 being scanned by the magnetic heads 23a and 23b can be specified.

The system control circuit 28 shown in FIG.

When fast forwarding or rewinding, the reel rotation speed ratio corresponding to the song to be played is read from the reel rotation speed ratio storage circuit 38, and the reel rotation speed ratio and the reel sent from the reel rotation speed ratio calculation circuit 37 are read out. When the difference between these values becomes equal to or less than a predetermined value by comparing the rotation speed ratio, that is, when the recording area of the song to be reproduced on the magnetic tape 22 is at the scanning position of the magnetic heads 23 a and 23 b. On the other hand, when it approaches a range within a certain tape length,
A function is provided to reduce the running speed of the magnetic tape 22 until the subcode data on the magnetic tape 22 can be read by the magnetic heads 23a, 23).

Next, the above-mentioned reproducing mechanism alternately plays back two songs from among the plurality of songs recorded on the magnetic tape 22. The timing chart shown in the above-mentioned No. 31EJ and the timing chart shown in FIG. This will be explained with reference to the timing chart shown in FIG.

Figure 4 (1) shows the state of recording of multiple songs on the magnetic tape 22.
Fig. 4 (2) shows a waveform diagram of the start ID (a signal for notifying the beginning position of a recorded multi-song), which is one of the subcode data, and Fig. 4 (3) shows the waveform diagram of the start ID (signal for notifying the beginning position of a recorded multi-song). The magnetic head 23 a on the magnetic tape 22 in operation,
The change in the position of 23b is shown by a solid line.

Here, in the same way as the conventional playback operation, when the Nth song and N. Let me explain by assuming that. First, at the time of To in Figure 3 (3), N
When the rising edge of star )-IDa corresponding to the th song is detected by the magnetic head 23a23b,
The N@th song is played back in the third [ ] (3) section T1. At this time, the reel rotation speed ratio calculated by the reel rotation speed ratio calculation circuit 37 at the time of TO is stored in the reel rotation speed ratio storage circuit 38 in association with the song number N of the NWth song.

Next, at time T2 in FIG. 3(3), the magnetic head 23a,
23b reads the rising edge of the star IDb shown in FIG. 3(2) (that is, when the beginning position of the N+1th song is detected), the operation shifts to searching for the N+5'#th song. This search is performed by extracting the start TD from the subcode data read by the magnetic heads 23a, 23b and counting the number in the fast-forward section T3 shown in FIG. 3(3). If you count the start ID 5 times, that is, the 311th (2) start I
When the rising edge of D c is detected) N+5+5@
It is assumed that the head position of the eye has been detected, and at this time T4, the reel rotation speed ratio calculated by the reel rotation speed ratio calculation circuit 37 is associated with the song number Nmo 5 of the N+5#th song, and the reel rotates. At the same time as the speed ratio storage circuit 38 is loaded, the reel motors 24a and 24b are braked.

Magnetic data 22 shows that even after the brake is applied due to the inertia of the reel, the reel goes too far by section T5, and at T6, the reel switches to reverse rotation, and in the next section T7, it moves past N+5+.
The edge of the start IDc corresponding to the 5th @ is detected. Even after the edge of the start IDc is detected, the magnetic tape 22 continues to run for a certain amount of time, and at time T8, the reel is switched to forward rotation and the magnetic tape 22 is fed at the speed of normal playback.

In this way, by continuing the reverse rotation for a while, N
The run-up section T9 necessary for +5+5@th regeneration is secured. After this, at T10, the star )-I D c
When the rising edge of T is detected, the interval T after this is detected.
At step 11, the N+5#th song is played.

More than! lJf? The point here is that the reel rotation speed ratios corresponding to the start position of the N'#th song and the start position of the N+5@th song are stored in the reel rotation speed ratio storage circuit 38 at the time of TO and the time of T4, respectively. This is different from the conventional reproducing operation described above, and f) the other points are completely the same as the conventional reproducing operation.

Next, at the time T12, when the rising edge of the start IDd shown in the 311J (2>) is detected, that is, N
When the start position of the #'th song is detected), the operation shifts to searching for the N-th song. This search is shown in Figure 3 (3
) The rewinding is performed through the rewinding section Tl 3a shown in FIG. In this rewinding section T13a, the magnetic heads 23a, 23b
Rewinding is performed at a fast running speed that exceeds the running speed at which the data recorded on the magnetic tape 22 can be read, and no search is performed by counting the start t-ID.

Instead, here, the reel rotation speed ratio corresponding to the Nth song to be played next is read out from the reel rotation speed ratio storage circuit 38 by the system control circuit 28, and the reel rotation speed ratio and the reel rotation speed ratio The current reel rotation speed ratio sent from the calculation circuit 37 is compared. When the difference between the read reel rotational speed ratio and the current reel rotational speed ratio becomes less than or equal to a predetermined value, that is, the beginning position of the song to be played is reached by the magnetic hand 23 = t, 23
Time point T14 when the scanning position approaches within a predetermined tape length by t+.
When reaching point a, the running speed of the magnetic tape 22 between this island and the section T L 5 a reaches the magnetic hend 23a.

23L), the speed is reduced to a level at which the subcode data can be read.

Next, when the rising edge of the start IDa corresponding to the Nth song is detected at T 16 a, the running continues for a certain period T 17 a, and then at T 18
At time a, the reel is switched to normal rotation drive, and the magnetic tape 22 is fed at the normal playback speed, and after this, through the run-up section T19a, the reel is switched to normal rotation drive as described above from time TO to time T2. With the reproduction operation, the Nth song is reproduced for the second time.

The progress from this second TO → T1 → T2 is described in the 111th
In 1ffl (3), it is shown as T20→T21→T22. At the time of T22, when the rising edge of the star corresponding to the N+IWth song)-ID a is detected, the N
The operation shifts to +5+5@th search.

This search is performed in the next fast forward section 723.

In this fast forward section T23, the magnetic head 23 i, t2
The magnetic tape 22 is fast-forwarded at a speed faster than the speed at which the magnetic tape 3b can read the data recorded on the magnetic tape 22.
The reel rotation speed ratio corresponding to +5+5@th is read out from the reel rotation speed ratio storage circuit 38 by the system control circuit 28, and this reel rotation speed ratio and the current σ) reel rotation sent from the reel rotation speed ratio calculation circuit 37 The speed ratio is compared.

When the time point T24 is reached when the difference between the read reel rotation speed ratio and the current reel rotation speed ratio becomes equal to or less than a predetermined value, the running speed of the magnetic tape 22 is reduced to the normal playback speed. Thereafter, when the rising edge of the start IDc corresponding to the N+5th song is detected at time T26 after passing through the run-up section T25, the N+5th song is played in the subsequent section T27.

In this way, the search is performed using the pre-recorded reel rotation speed ratio without detecting the start ID recorded on the magnetic tape.
In the fast forward section T23 from 22, the magnetic herad 23
The magnetic tape 22 can be fast-forwarded at a high speed that exceeds the running speed at which subcode data a and 23b can read the subcode data recorded on the magnetic tape 22, and the time required for the search operation can be shortened.

After that, when the rising edge of the start ID d corresponding to the N+6th point is detected at time T28, as shown in FIG.
), the search for the Ni-th song is performed in the same way as the progression from T12 to T 19a (in the 41st ffi (3), the same progression is shown as T28 → T35).
, and thereafter T20→T21-T22 in Figure 4 (3)
→The same operation as T23...T36→T37→T38
→T39... is repeated.

Effects of the Invention As described above, according to the playback device of the present invention, the position of each main data on the magnetic tape is replaced with the rotation speed ratio of the reel and stored, and the stored rotation speed corresponding to the main data to be played back is stored. The main data for playback purpose is searched by comparing the speed ratio with the reel rotation speed ratio during fast forwarding or rewinding, so when searching for main data during fast forwarding or rewinding, the magnetic tape Most of the traveling section can be searched by running at a high speed exceeding the speed 1': T, at which the head can read the subcode data recorded on the magnetic tape, and the time required for the search operation is can be significantly shortened.

[Brief explanation of the drawing]

1st (2ff) is a block opening showing the configuration of a playback device which is an embodiment of the present invention, FIG. 2 is a graph showing the relationship between the running position of the magnetic tape and the reel rotational speed ratio, A timing chart showing the first playback operation of the playback device and the playback device of the example, FIG. 4 shows the playback of the example,
A timing chart showing the second and subsequent playback operations of the device; FIG. 5 is a block diagram showing the configuration of a conventional playback device;
FIGS. 6, 7, and 8 [J are explanatory diagrams showing the relationship between the magnetic head and the recording track on the magnetic tape during playback, fast forwarding, and rewinding, respectively, in a digital audio tape recorder. . 21... Rotating drum, 22... Magnetic chi 1.23a
. 23b...Magnetic head, 24a, 24b...Reel motor, 25a, 25b...Rotation speed detection sensor, 2
8... System control circuit, 36... Key input circuit, 37... Reel rotation speed ratio calculation circuit, 38...
・-Reel rotation speed ratio memory circuit agent Patent attorney Number of strokes Keiichi Figure 2

Claims (1)

[Claims] A magnetic tape on which a plurality of main data and a plurality of subcode data related to each main data are sequentially recorded is wound from a supply reel to a take-up reel. a reproduction means for reading each data with a head and reproducing the main data; a head position detection means for detecting the head position of the main data from the subcode data read by the head; In a reproducing apparatus having a fast forwarding means for fast forwarding and a rewinding means for rewinding a magnetic tape from a take-up reel to a supply reel, the input means for inputting a command signal to search for main data to be reproduced on the magnetic tape; a rotational speed ratio detection means for detecting the rotational speed ratio of the reel and the take-up reel; and a rotational speed ratio detection means that detects when the head is scanning each main data recording area on the magnetic tape. A storage means for storing a rotational speed ratio in association with main data; and a storage means for reading out from the storage means a rotational speed ratio corresponding to the main data for reproduction purpose specified by the input means, and storing the rotational speed ratio at the time of fast forwarding or rewinding. By comparing the rotational speed ratio detected by the detection means with the rotational speed ratio read out, it is detected that the recording area of the main data to be reproduced on the magnetic tape approaches the scanning position of the head, and 1. A playback device comprising tape speed control means for reducing the running speed of a magnetic tape until code data can be read.